A Pragmatic Trial to Determine the Benefit of Behaviorally Enhanced Exercise Incentives and Corticosteroid Injections in Osteoarthritis of the Knee

Knee osteoarthritis (KOA) is one of the most prevalent and disabling conditions among Veterans and accounts for high morbidity and high costs for the VA. Management of KOA is challenging as there are few consistently effective treatments other than joint replacement. Importantly, chronic reductions in physical activity in patients with KOA may worsen pain, physical function, and exacerbate the metabolic consequences of obesity. Moreover, the greater mortality observed in symptomatic knee OA populations is likely mediated through its effect on physical activity. The current proposal aims to derive preliminary data to support a large pragmatic trial testing the impact of interventions geared towards improving physical activity and function in KOA patients.

Promoting physical activity has been shown to be helpful in reducing pain and improving function in KOA and other groups. However, promoting behavioral change in the arthritis population is a significant challenge. The group has shown that social incentives [and gamification] derived from concepts from the field of behavioral economics to promote behavioral change and increase physical activity can be both practical and effective in other settings. The investigators' group is studying incentives in patients with inflammatory arthritis with the goal of addressing fatigue, pain, and deficits in physical function. The incentivization of physical activity using this approach represents a novel intervention for the managing symptoms of KOA and to improving overall health.

Analgesic therapies can help KOA patients participate in exercise therapy. However, whether corticosteroid injections, a commonly used medical therapy for KOA pain, has a positive impact of physical activity is unknown and is an additional important question addressed by the current proposal. Despite widespread use, definitive data demonstrating a consistent benefit of corticosteroids are lacking. A large randomized trial recently tested the effects of repeated corticosteroids injections every 3 months for a period of 2 years on patient reported pain as well as progression of disease measured by magnetic resonance imaging (MRI). This study demonstrated no improvement in pain compared to saline injections. In addition, a small but statistically significant decline in cartilage thickness on MRI was observed, raising a concern for side effects. These recent data might suggest that corticosteroid injections result in more harm than good, and may discourage providers from performing this intervention. However, there are critical weaknesses to this study. Pain and function were only assessed at 3-month intervals, while previous trials have suggested that peak benefit is expected at 4-8 weeks. Moreover, the clinical and biologic significance decrease in cartilage thickness is unclear.

The investigators propose to fill these important knowledge gaps with an innovative and efficient pragmatic clinical trial with a factorial and crossover design. A large and definitive practical trial would lead to better understanding of the clinical effectiveness of these interventions, the meaningfulness of their combined impact, and the subgroups that are most likely to derive benefit. This clinical trial will leverage unique resources available through the Penn Center for Innovation to better capture important patient-reported outcomes in real-time through a web-based platform. The study will also test the feasibility of a crossover and factorial design to improve efficiency and reduce confounding. Each patient will receive each intervention (saline, corticosteroids) in random order over 1 year. A factorial design will be employed and will randomize participants to receive social incentives with gamification to promote increases in their physical activity. To accomplish these aims, the investigators will utilize innovative mobile applications for smart phones and wearable activity trackers through the Way-to-Health platform and assess, in real time, the impact of the intervention on patient-reported function and pain as well as physical activity. The technology will allow for the recording of outcomes as they occur, between clinic visits, thereby avoiding information bias due to poor recall. It will also provide real-time assessment of symptoms, providing granular assessments of response over time.

Aim 1: To determine whether an incentive based on behaviorally-enhanced gamification can improve physical activity among patients with KOA and reduce self-reported pain and disability. The intervention will result in sustained improvements in average daily step counts over 10 months.